Tech Update: Filling Equipment

Faster fill times are nice, but a host of other considerations also are part of manufacturers’ value calculations. Those needs are evident in the systems being developed.

Individual-portion meals represent a growing product segment that used to rely on manual filling but has largely converted to automated systems because of speed and precision. Source: Hinds-Bock.

For both liquids and solids, product identity begins at the filler. Whether it arrives continuously or as part of a batch, once food flows, drops or is wrapped in its primary container, a discreet unit is created. It is a critical transfer point, where speed, precision and hygiene are essential.

Because filling operations easily can become choke points, speed always has been a priority. In many cases, it was viewed as the only factor in production profitability. But that calculation ignores the cost of unscheduled downtime, product waste, rework and, in extreme instances, defects that require recalls. Speed remains important, but optimum speed seldom is full throttle.

“Throughput is the name of the game,” allows Gail Barnes, vice president-technology and packaging for Dairy Management Inc., which manages the Innovation Center for US Dairy in Rosemont, IL. But downtime and quality issues require a nuanced approach. Sustainability considerations and hygienic design must be addressed. For example, many producers are exploring alternatives to plastic packaging, and that has a direct impact on filling operations. “It’s all about taking a holistic view and adopting a collaborative approach,” says Barnes, and several packaging and filler companies are working toward “full-on collaboration and joint ventures.”

Collaborations have played a critical role in the commercialization of high-pressure processing (HPP), the batch process that subjects packaged foods to pressures of 80,000psi or more to denature any microorganisms. Rapid loading and unloading were identified early on as key to payback on the cost of the presses. A partnership between NC Hyperbaric, which introduced the first horizontal HPP press, and Gridpath Solutions Inc. effectively addressed the throughput issue (see “Through a chamber, quickly,” Food Engineering, November 2005). More recently, Uhde High Pressure Technologies GmbH has worked with Multivac GmbH to devise a turnkey system that combines filling, packaging, material handling and processing.

Turnkey systems that not only fill but also deliver ingredients to the filling point are in demand. Source: Multi-Fill Inc.

Based in Germany’s Allgäu region, Multivac is most associated with horizontal thermoform packaging machines, with the largest units filling and sealing 150 units or more per minute. The company also builds robotic loading systems, and it formed a strategic partnership with Uhde to develop “a totally integrated, automated line” for HPP, according to Multivac engineer Tobias Richter. “We see HPP as one of the fast-emerging technologies for [improved] food safety. It was a logical step to integrate a Uhde press into our system.”

Richter, product manager for the HPP system, estimates two to four tons of packaged foods per hour can be processed with the fully automated system. Efficiencies are gained by tying filling and processing together in the same room and by the semi-continuous nature of product infeed. A modified steel cylinder was designed to allow a robotic gripper to load packaged goods. Richter developed the software that optimizes loading, based on the geometry of the packages. The most significant advancement is in process control of the press itself: Short breaks that he calls “holding torque” during depressurization make the use of MAP packaging possible. These short pauses allow package polymers to regenerate and withstand compression rates higher than the 16 percent vacuum packages undergo in the press. Previously, few options to vacuum packaging existed for HPP.

A single form/fill/seal machine and robotic loader can feed multiple presses. Automated unloading and labeling units complete the system, the first of which will be installed by New Zealand Food Innovation Manukau Ltd.

Weighing and staging finished goods is an integral part of filler technology. Source: Bob Rossiter.

End-of-line solutions

HPP mimics retort’s in-container sterilization process. Typically, products arrive at the filler already cooked. Cartoning, case packing, printing and palletizing follow. Turnkey systems encompassing all these functions plus filling are rare, but the unification of machine builders under the Oystar North America umbrella will result in end-of-line solutions that extend from filling to palletizing.

Early this year, Packaging Technologies, a Davenport, IA fabricator of chub, aerosol and rotary liquid fillers, was combined under the Oystar banner with RA Jones, best known for secondary packaging systems. Oystar also owns Hassia, a major supplier of liquid form/fill/seal machines. That division soon will be folded into Oystar North America. “Our idea was to have one R&D department, one customer-contact point, one face in the market,” explains Tom Graf, CEO of Oystar Group, Stutensee, Germany. Centers of competence teams are being organized to improve f/f/s, dosing and other technologies. By pooling in-house expertise and tapping the financial resources of a larger organization, Graf expects greater success in bringing innovative fillers to the market.

Oystar’s goal is to develop packaging lines for middle-tier food and beverage companies, as well as the global companies its business units traditionally have served. “More and more, global companies are moving into developing and under-developed countries where people don’t have the money to buy large cups,” says Graf. To ensure the same level of package integrity that is delivered by Hassia’s aseptic f/f/s cup fillers, Oystar has developed stick-pack machines for finite quantities. But that constitutes a specialty application, and Oystar mostly will steer clear of the stick-pack market, he adds, despite the format’s growing popularity.

In neighboring Switzerland, Bosch Packaging Systems AG is taking a much different approach. The OEM recently introduced a new high-speed stick-pack system that combines primary and secondary packaging for powders and free-flowing ingredients. Up to 1,000 sticks per minute in quantities of one to four grams can be formed, filled and sealed by one machine, with accuracies within 1.7 percent of the target weight, according to Uwe Jansen, vice president-product line free flow, Beringen, Switzerland.

“Stick packs started on the pharmaceutical side, particularly in France, and now they are migrating to food powders and nutraceuticals,” Jansen says. The format is proving popular throughout Europe, where some manufacturers are converting single-serve packages to sticks, reducing package materials by up to a fifth. “Handling 1,000 sticks a minute is not so easy,” however, and Bosch felt compelled to combine the machine with an automatic cartoning unit, he says.

European food manufacturers are focusing on OEE and taking their packaging cues from pharmaceutical manufacturers, Jansen believes. That focus puts a premium on precision filling and hygienic designs in machines that are easier to clean and minimize human interface.

US food companies have similar concerns, and best-in-class fillers are evolving as OEMs standardize on the most demanding requirements of end-users, according to Christine Marchadour, founder and part-owner of Multi-Fill Inc., West Jordan, UT. Angled frames, acid-treated welds to prevent corrosion and a shift to 316 stainless from 304 exemplify the sanitary improvements that have occurred in recent years. Efficiency improvements include positive drives that reduce slippage and result in greater fill consistency. Faster changeovers are possible with today’s machines, and Multi-Fill offers a “quick clean mode” to clean in place between product runs.

Growth in single-serve meals has been a boon for suppliers like Multi-Fill. A decade ago, copackers still relied on hand filling, accepting deviations of about 5 percent from target fill weights (see “Precision filling as requested,” Food Engineering, December 2004). Conversion to volumetric fillers narrowed deviations to 1.5 percent. Today’s production environment is even more demanding, and OEMs are trying to keep pace. For cooked rice and cooked pasta meals, “the machine works better if the product arriving at the machine is consistent,” she points out, and that presumes delivery of cooked product in a timely manner to the filler-a level of process control that doesn’t always exist (see related story on page 54). Those issues are beyond an OEM’s control, of course, so they focus on concerns they can impact.

“Worker safety, as well as food safety, has become a big issue,” observes Marchadour. Safety covers that suppress arc flashes when panels are opened are an example of the modifications that are being made to keep humans out of harm’s way.

This artist’s rendition shows an automated filling, loading and unloading system for multiple high-pressure processing (HPP) presses. Multivac engineers developed the turnkey system in partnership with Uhde, another German OEM. Source: Multivac Inc.

Caution: Speed bumps ahead

Some of the fastest fill times known to man were reached in the 1990s, when rotary fillers that could put 100 bottles of beer on the wall every 12 seconds were being installed. If filling speed was analogous to the space race, technology would have pushed rotary filling from the moon to Mars in the last decade. But manufacturing priorities shifted to greater flexibility and away from ever-higher throughput.

The speed race ended years ago for Fogg Filler Inc. The Holland, MI maker of rotary fillers topped out at 1,000 units a minute. Today, few of the dairies and beverage bottlers that use its systems strive to exceed outputs of 500 units a minute. Instead of faster fill rates, end-users want quicker changeovers, less product waste and enhanced hygiene, according to Susan Lamar, sales & marketing director.

Filler turrets that do their work in the middle of the packaging area have been replaced by clean-room enclosures which are fed Class 100 HEPA-filtered air. “For liability reasons, we do not install fillers without sufficient guarding,” Lamar explains. An immediate payback from hygienic enclosures is longer shelf life: An Arkansas dairy extended its best-by code dates 10 percent recently after installing a Fogg monoblock system. Other contributions to overall equipment efficiency are a bottle sanitizer that uses ultraviolet light to achieve up to a six log reduction in microbial contaminants, and a trough system that allows operators to funnel product out of the filler bowl and return it to the beginning of the production line for rework when a changeover occurs. “Before, you had to dump it down the drain,” she says.

“Your quality is only as good as the weakest link in your chain,” DMI’s Barnes points out, and filling and sealing operations are the most likely post-processing contamination points. She applauds supporting technologies like positive air pressure, UV lamps and package sterilization via electron beam for their contributions to filling safety.

“There is more of a push for sanitary design than faster speed,” adds Lamar, an observation with which few would disagree. Just as Multi-Fill has responded to manufacturer specifications requiring compliance to the sanitary design principles outlined by the American Meat Institute, Hinds-Bock Corp. has redesigned its fillers to eliminate pooling of washdown water. It has also replaced square support bars with tubes and substituted angled surfaces for flat ones. “Our sanitary pumps are CIP,” notes Lance Aasness, vice president-sales and marketing at Bothell, WA-based Hinds-Bock.

Speed, precision and flexibility also are critical, Aasness adds. Servo-driven pumps are incorporated in the firm’s fillers for flowable products, such as sauces and dressings, and for products with particulates, such as macaroni and cheese. “Servo-drive technology provides high-speed depositing with custom-tuning of filling parameters to control the appearance of each fill, as well as velocity,” he says.

Speed is and will remain the comparative measure for various classes of fillers. Nonetheless, manufacturers need to address a host of other considerations, as well, and the cost of product defects and downtime can quickly erode the advantage of speed when calculating return on investment. Cognizant of the balancing act faced by manufacturers, filler suppliers are engineering equipment that goes well beyond simple speed calculations.

Failure analysis includes all aspects of machine performance

Poor machine design is one of the major sources of process variability and must be considered and quantified in a failure mode and effect analysis (FMEA), even when another aspect of the process is suspected of being the root cause of waste, according to Tina Kovach, continuous improvement manager and a Six Sigma master black belt at Dawn Food Products Inc., Jackson, MI.

In a presentation at Food Engineering’s 2011 Food Automation & Manufacturing Conference, Kovach outlined the 10 steps of a FMEA evaluation, including the importance of defining and analyzing the “five Ms” of any process: man, machine, method, materials and measurement. A disciplined approach to process improvement requires defining failure for each M and then quantifying the frequency and severity of those failures.

To illustrate, Kovach cited a project she oversaw at Nestlé Prepared Foods. “It was pretty obvious we had excess labor” in the filling operation, she recalled, but that didn’t preclude quantifying the frequency of unfilled and under-dispensed containers exiting the depositors. A multi-function team then began the FMEA process by assigning a risk priority number based on the severity, occurrence and detection probability to each failure mode. That exercise fed into a multi-step process resulting in corrective actions.

“We had to measure out every piece of the five Ms,” she said. “What is the failure with the machine, what is the failure with the people?” In Nestlé’s case, filling failure was not mechanical per se but product infeed: When incoming ravioli cooled, it stuck, causing clumping and poor dispensing. Six workers were positioned downstream to inspect and correct underfilled trays. Besides the labor issue, “people were putting food into trays just because they were standing there and were bored,” Kovach said. Instead of six workers, one was deployed to break up incoming pasta as necessary. Elimination of the other workers system-wide resulted in savings of more than $2 million in labor and product-giveaway costs.

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